Integrated circuit based microsensor chemical detection system and elements

ABSTRACT

A chemical detection system on an integrated circuit includes microsensor elements adapted to detect target chemical and/or target environmental conditions. The chemical detection system generally includes carbon nanotubes as the microsensor elements, magnetoelectronic processing components for interpreting the CNT state, non-volatile memory for storing the detection state, and a combination of readout options, including transmitting antennas and micromechanical structures for controlling an expression of a readout substance.

RELATED APPLICATION DATA

The present application claims the benefit under 35 U.S.C. 119(e) of thepriority date of Provisional Application Ser. No. 62/588,583 filed Nov.20, 2017, which is hereby incorporated by reference. This application isalso related to the following applications, all of which are filed onthis same date and incorporated by reference herein:

Microsensor Chemical Detection Mixture; Ser. No. 16/196,629;

Microsensor Coated Article; Ser. No. 16/196,640;

Microsensor Detection Process; Ser. No. 16/196,654 now U.S. Pat. No.10,382,039.

STATEMENT AS TO GOVERNMENT RIGHTS

The present application is related to application Ser. No. 14/133,055that was filed during a time when the inventor was employed by the NavalResearch Laboratory as part of Task Area MA02-01-46, Work Unit T042-97,and was developed as a result of efforts associated with NRF grantsfunded by MEST (2010-0000506, 2011-0012386 and 2012-0005631), theindustrial strategic technology development program funded by MKE(KI002182), the Dream project, MEST (2012K001280), GRL and the Office ofNaval Research. To the extent they are not otherwise alienated,disclaimed or waived, the government may have certain limited rights touse, practice or otherwise exploit some or all portions of theinventions herein.

FIELD OF THE INVENTION

The present application is directed to the structure and use ofminiaturized, customized sensors incorporated on the surface or withinthe body of an article for the purpose of detecting a target element,compound or environmental condition. The miniaturized sensors areapplied, among other ways, using an aerosol delivery system, apaint/printing process, or as part of a manufacturing process for thearticle. The invention is particularly suited for detecting hazardousmaterials in security applications.

BACKGROUND

Common hazardous materials, including explosives, corrosives andbiohazards, are typically solid or liquid. Associated with thesematerials are volatile (gaseous) chemicals. These volatiles may be thegaseous form of the hazardous material or may be a molecule that derivesfrom a simple chemical reaction of the hazardous material with ambientconditions.

The traditional method of detecting chemical or biological agents,including those associated with hazardous materials, is described withthe schematic sketch in FIG. 1. The sketch and discussion of the sketchare summarized from material in Ref. [1]. A conventional sensor system100 that studies or identifies the chemical components of an analyte(sample) 110 consists of: (1) a chemical detection or recognitionelement 120, (2) a transducing element 130, and (3) a signal-processingelement (including memory) 140. The chemical detection element 120 iscomposed of some sensing material. It interacts with a sample on asubstrate or in the environment and generates a response. The transducer130 reads the response from the chemical detection element and convertsit into a quantifiable signal in a format that can be used as data thatare input to the signal processor. The signal processor 140 analyzes theinput and determines if a target substance has been detected. It mayalso quantify the relative amount of the substance. The Readout 150 fromthe system processor includes an output 160 that is provided to a largerinformation system or network.

The chemical detection element 120 is the basis of the system. It ischaracterized by its response, recovery, selectivity and sensitivity.Categories of materials for the chemical detection element include metaland metal oxide semiconductors, solid electrolytes, insulators,catalytic materials, polymers and composites. The detection element maybe unique and customized for a given target molecule. The detectionelement may undergo a structural change or may respond to electric,electrochemical or optical stimulation, and the transducer 130 functionsby sensing a change of state associated with one of these responses. Thedetection element may respond by exhibiting a plurality of differentstates, either discrete or an analog spectrum of states. The signalprocessor 140 interprets the information from the transducer to confirmthat a change has occurred in the detecting element and identifies thechanged state, or identifies which of a plurality of states is present.In such instances the entire system/process of identifying andconfirming the presence of the target material is performed by elementsdistinct from the article (in this case the analyte or substrate)itself. An example of this prior art approach is a stationary (static)system that detects biohazards. In a specific example, the target isanthrax and the article in question (a postal letter or package) isprocessed by a customized, isolated chamber as the article passesthrough a mail delivery facility.

System 100 may have multiple and changeable components, but typically isa macroscopic system with a large physical footprint. The signalprocessor 140 may be a central computing system or a smaller system suchas a desktop or laptop computer. The chemical detection element 120 anda matched transducer 130 may be designed for detection of a specifictarget substance and a variety of these components may be connected tothe signal processor.

In the example given above, an article (postal letter or package) servesas a substrate that may or may not include the target analyte and thearticle is provided to the apparatus in the course of commerce andtransactional traffic. In another method of operation, samples aregathered from the field, brought to the system and introduced to thesystem for analysis. The system apparatus has a large footprint and isrelatively expensive. Although the system may have changeablecomponents, the flexibility is severely limited. These are disadvantagesof this prior art.

Recent developments in microfabrication have enabled the invention ofnew kinds of chemical or biological sensor systems. The new system ischip-based, miniaturized, adaptable to different targets andinexpensive. The system builds on the older concept of asystem-on-a-chip. A system-on-a-chip may include one or more sensors,digital information processing circuits, memory, and means for input andoutput of data. The Remote Independent Microsystem (RIM) was disclosedin U.S. Pat. No. 9,432,021. A RIM is micro- or nano-fabricated withdimensions smaller than a traditional system-on-a-chip. It isinexpensive and designed to be expendable after a single use. Itoperates with very low power and has a long operational lifetime.Detection of chemical or biological agents was mentioned in '021 butthis application deserves further consideration.

The new sensor system requires chemical detection elements 120 that arefabricated on micro- or nano-processed chips. The detection elements canbe tailored to respond to a specific agent or to a class of agents.Several detection elements with uniquely tailored responses can befabricated on a single chip. A selection of one element (or of a subsetof several element) can be made programmatically by activating theappropriate areas of the chip.

A variety of chemical detection elements are suitable formicrofabrication on chips. As one example, there have been manydevelopments in the last two decades concerning the use of carbonnanotubes (CNTs) as detecting elements, typically in the form of adedicated/integrated sensing/detection portable system. An interactionbetween a target molecule and a CNT changes the electric resistivity ofthe CNT. The interaction occurs when the volatile molecule comes incontact with a surface of the CNT. This change of resistive state is thebasis of the CNT sensor.

It is not currently practical to fabricate a robust sensor using asingle CNT. Therefore an array of CNTs is typically fabricated on top ofa pair of interdigitated thin film metal electrodes to form a detectingelement. The transducer is a circuit that measures the resistance of thearray. The transducer may have the simple form of a current source andvoltage detector or the inverse, a voltage source and current detector.The resistance measurement of the transducer is sent to the signalprocessor where the value is compared with an initial referenceresistance value stored in memory. A comparison of the values determineswhether an interaction has occurred and the presence of the targetmolecule can be deduced/confirmed.

An example of a detecting element 200 using CNTs is shown in FIG. 2.Thin film metal wires 220 and 240 form a pair of interdigitated currentand voltage electrodes. An array of CNTs 230 is distributed across thesurface of the leads and they adhere to the surface. To measure theaverage resistance of the array, a small current is applied from 220 to240 and a voltage is measured from 220 to 240. Alternatively, voltagecan be applied and current measured. Detector arrays of this kind havebeen fabricated with lateral dimensions on the order of 10 microns [2].

The process using CNTs is flexible enough that it can be modified in anumber of ways in order to detect a variety of target molecules usingother forms of chemical interactions. For example, the CNTs can becoated with a thin layer of a chemically active material such as apolymer. An interaction occurs when the volatile molecule comes incontact with the polymer. If the polymer is altered or destroyed by theinteraction, the resulting change in the surface state of the CNT causesa corresponding change in resistance. The resistance is measured by thetransducer and the process for deducing the presence of the targetproceeds in the same way as described above. A different choice ofchemical coating results in sensitivity to a different target molecule.

Chemical detection elements based CNTs represent an approach that hassuccessfully demonstrated microfabricated prototypes with dimensions onthe order of ten microns or less. Other techniques also are plausible.Traditional detection elements (fabricated with macroscopic dimensions)commonly use polymers. Polymers are organic macromolecules dominantlycomprised of carbon and hydrogen atoms, and include heteroatoms such asnitrogen, oxygen, sulfer, phosphorous and etc. as minor constituents.They are characterized by high tailorability, having a broad range ofproperties and versatility. Both the bulk and surface of a polymer maycontain active functional groups which can respond as a chemical sensor.Properties that can be sensed by a transducer include physical and/orchemical (such as mass or volume), electrical (resistivity) and optical.

In addition to these chemical targeted sensors, other environmentalcondition detecting elements in printed electronic form are known in theart and are sufficiently small (˜4 cm by 8 cm) to be affixed (with anadhesive or similar technique) to packaging or other articles ofinterest. These elements are sensitive to conditions such astemperature, humidity, pressure, flow or light. As a specific example,in transporting certain pharmaceutical products care must be taken toensure that they are not exposed to temperatures over a certainthreshold. See e.g., U.S. Pat. No. 9,742,466 incorporated by referenceherein.

Some additional useful background information for the present inventioncan be found in: Fundamentals of Sensing Materials. Volume 3: Polymersand Other Materials, edited by Ghenadii Korot Tcenkov, Momentum Press,LLC, New York, N.Y. (2010); Chapter 1, Polymers in Chemical Sensors, B.Adhikari and P. Kar, page 2 and FIG. 1.1; and Li, J., Lu, Y., Ye, Q.,Cinke, M., Han, J., and Meyyappan, M., Nano Lett., Vol. 3, p 929 (2003);Li, J. Carbon Nanotubes: Science and Applications, Chapter 9, Editor: M.Meyyappan, CRC Press, Boca Raton, Fla., USA (2004) both of which areincorporated by reference.

SUMMARY OF THE INVENTION

An object of the present invention, therefore, is to overcome theaforementioned limitations of the prior art. It will be understood fromthe Detailed Description that the inventions can be implemented in amultitude of different embodiments. Furthermore, it will be readilyappreciated by skilled artisans that such different embodiments willlikely include only one or more of the aforementioned objects of thepresent inventions. Thus, the absence of one or more of suchcharacteristics in any particular embodiment should not be construed aslimiting the scope of the present inventions.

An object of the present invention, therefore, is to overcome theaforementioned limitations of the prior art. It will be understood fromthe Detailed Description that the inventions can be implemented in amultitude of different embodiments. Furthermore, it will be readilyappreciated by skilled artisans that such different embodiments willlikely include only one or more of the aforementioned objects of thepresent inventions. Thus, the absence of one or more of suchcharacteristics in any particular embodiment should not be construed aslimiting the scope of the present inventions.

An object of the present disclosure therefore is to overcome some of thelimitations of existing chemical detection systems, specifically, bymaking the detection elements smaller so that they can be deployed intonew environments, are easier to deploy and are more functional.

A related object therefore is to provide a chemical detection system thacan be situated on a single semiconductor chip, comprising: a sensorcircuit configured with a resistance state that is responsive to thepresence of a target chemical and/or target environmental condition whenexposed to a target environment; a transducer coupled to the sensorcircuit configured to detect the resistance state and generate an outputcorresponding thereto; and a magnetoelectronic (ME) processing circuitcoupled to the transducer and including one or more magnetoelectronicgates adapted to perform a first sequence of operations during anoperational mode on the output from the transducer; a detection outputis generated by the ME processing circuit having a detection value basedon the first sequence of operations confirming the presence of thetarget chemical and/or target environmental condition; the ME processingcircuit is configured to not consume power in a quiescent mode; anon-volatile memory coupled to the ME processing circuit for storing thedetection value; a readout substance situated in a storage chamber ofthe single semiconductor chip; and one or more micromechanicalstructures responsive to the detection output, and adapted to cause thefirst readout substance to be released from the storage chamber inresponse to the detection value; with this type of structure a presenceof the target chemical and/or target environmental condition can bedetermined by detecting the first readout substance released from thechamber.

In preferred embodiments the sensor made of a carbon nanotube (CNT). TheCNT sensor circuit can also be coated with a polymer that reacts in thepresence of the target chemical.

A second storage chamber can be connected to the storage chamber forstoring a second readout substance. In some applications, a membraneseparating the storage chamber and the second storage chamber isprovided, and which is adapted to be ruptured by the one or moremicromechanical structures to permit mixing of the first readoutsubstance and the second readout substance. For some applications, athird readout substance can be caused to result from the mixing. Inother applications the membrane rupture permits release of the firstreadout substance to an exposed external portion of the singlesemiconductor chip.

The target chemical can be a chemical and/or biological agent hazardousto living organisms.

Depending on the application, the chemical detection system and thefirst readout substance can be made to be detectable or substantiallyundetectable to an unaided human visual system.

Because of their small size, one or more single semiconductor chips canbe affixed to or embedded in a paper based substrate or an article ofclothing. They can also be incorporated and made part of a solid powderor liquid mix.

Due to their low expense and ease of manufacturability, they can also beimplemented as one-time disposable detectors of the target chemical.They can be deployed in significant quantities in a large distributedtargeted area to increase the likelihood of detecting targetenvironmental conditions and/or chemicals.

The system can also include a transmitter and antenna situated on thesingle semiconductor chip adapted for communicating a result of thedetection output using electromagnetic radiation. For example, theantenna can be adapted for near field communications with a separatetarget chemical interrogation system, which can be microwaves, pulses,etc. The antenna enables passive readout and is activated by a readoutpulse generated by the ME circuit. A voltage bit stream from the storeddetection value can be superposed with a reflected microwave signal toform a signal transmitted to an interrogating receiver.

In other applications, the first chemical readout can be detected usingan optical reader responsive to a wavelength of light reflected by thefirst readout substance and/or a separate chemical resulting from thefirst readout substance.

A further aspect of the invention concerns a detection mixture ofchemical detection elements, comprising: a first component including oneor more non-detecting chemical elements in the detection mixture; thechemical detection elements being incorporated as a second component ofthe detection mixture and comprising a single integrated circuit onwhich is situated: a sensor element configured with a sensor stateresponsive to the presence of a target chemical when exposed to a targetenvironment; a transducer coupled to the sensor element and configuredto detect the sensor state and generate an output corresponding thereto;and a magnetoelectronic (ME) processing element coupled to thetransducer and adapted to perform a first sequence of operations duringan operational mode on the output from the transducer; wherein adetection output is generated by the ME processing element having adetection value based on the first sequence of operations confirming thepresence of the target chemical; a readout substance situated in astorage chamber of the single semiconductor chip; and one or moremicromechanical structures responsive to the detection output, andadapted to cause the first readout substance to be released from thechamber in response to the detection value; with this mixture, apresence of the target chemical can be determined by detecting the firstreadout substance released from the chamber.

Depending on the target environment or use, the first component of thedetection mixture can be a solid powder, including for example dry tonerparticles contained within a printer cartridge. The chemical detectionelements are engineered and manufactured to be approximately the samesize as toner particles constituting the first component of thedetection mixture.

In other applications the first component of the detection mixture is aliquid ink or dye, which be applied and adhere to an article such as afabric, a paper based substrate, and similar materials which can becoated with a surface layer. In still other environments the mixture canbe incorporated as part of regular liquid suspension, or an aerosolsuspension within a pressurized container, adapted with a nozzle tospray the detection mixture onto a target surface.The detection elements can be configured to respond to environmentalconditions, including temperature, humidity, light or radiationassociated with the target environment. In such instance, one or morethin film metal resistance elements can be used to respond to a targetenvironmental. These environmental condition detection elements can beincorporated within an RFID tag and made readable by a passive dipoleantenna microwave based reader.

Yet another object of the present invention is to provide a physicalarticle adapted with chemical detection capability based on integratedchemical detection elements, comprising: a first body portion of thearticle; the chemical detection elements being incorporated on a surfaceof the first body portion; and each of the chemical detection elementscomprising a single integrated circuit on which is situated: a sensorelement configured with a sensor state responsive to the presence of atarget chemical when exposed to a target environment; a transducercoupled to the sensor element and configured to detect the sensor stateand generate an output corresponding thereto; a magnetoelectronic (ME)processing element coupled to the transducer and adapted to perform afirst sequence of operations during an operational mode on the outputfrom the transducer; a detection output can be generated by the MEprocessing element having a detection value based on the first sequenceof operations confirming the presence of the target chemical; a readoutsubstance situated in a storage chamber of the single semiconductorchip; one or more micromechanical structures responsive to the detectionoutput, and adapted to cause the first readout substance to be releasedfrom the chamber in response to the detection value; a presence of thetarget chemical having made contact with or in the vicinity of thearticle can be determined by detecting the first readout substancereleased from the chamber.

Depending on the application, the physical article can be an article ofclothing, paper, packaging, and similar articles that could come intocontact with a target chemical and to which the elements can be affixedor embedded. In some security applications the elements are incorporatedwithin an ink mixture on a sheet of paper, or as part of the fibersmaking up the body of the paper itself.

Other related objects of the invention pertain to methods of detectinghazardous materials, in which the chemical detection elements areembedded or affixed to including the process of: providing a firstphysical article; embedding a chemical detection element onto a surfaceportion of the physical article, wherein each of the chemical detectionelements comprises a single integrated circuit (IC); generating a sensorstate based on a sensor element on the single IC, which sensor stateresponds to the presence of a target chemical on and/or near the firstphysical article; generating a transducer output with a transducer onthe single IC coupled to the sensor element which detects the sensorstate and generates an output corresponding thereto; interpreting thetransducer ouput with a magnetoelectronic (ME) processing element on thesingle IC; the ME processing element generating a detection value basedon the interpreting the output confirming the presence of the targetchemical; and generating a chemical payload output responsive to thedetection output on the single IC to indicate prior exposure of thefirst physical article to the target chemical, either directly on or insome cases in the vicinity thereof.

Again, depending on the target application, the chemical detectionelement is applied as a liquid, as a spray, or in solid form to thephysical article. In surveillance situations, the article can be placedin a target environment and recovered after a predetermined period whereit can be read out. In some surveillance instances the physical articlecan be part of an enclosure for a room, a transportation vehicle, afixture or piece of furniture within a room, etc.

In other instances the surveillance article is in a paper form (letter,flyer, package, coupons, etc.) that is expected to be handled by a humantarget for monitoring and detection of minute traces of the targetchemical on such person's hands, clothes, body, etc.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified diagram of the basic components of a conventionalchemical sensor system;

FIG. 2 is a top view sketch of a carbon nanotube (CNT) based detector;

FIG. 3 shows the structure of a RIM based chemical sensor systemimplemented in embodiments of the present invention;

FIG. 4 is a simplified diagram identifying the basic components of achemical sensor system implemented in accordance with the teachings ofthe present disclosure;

FIG. 5 is a simplified flowchart of the basic steps of a chemical sensordetection process implemented in accordance with the teachings of thepresent disclosure;

FIG. 6 is a simplified flowchart of the basic steps of a preferredchemical sensor detection process, using RIMs embedded in an article,implemented in accordance with the teachings of the present disclosure;

FIG. 7 is a simplified flowchart of the basic steps of a preferredchemical sensor detection process using RIMs dispersed as an aerosolimplemented in accordance with the teachings of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure provides new embodiments of micron-sized magneticbased chemical/environmental condition detectors that are well suitedfor a number of new applications, and which are affixed or applieddirectly as a thin coating or layer to articles using printed, coated orsprayed processes, including through aerosol applicators. Thesedetectors are based on variants of magnetoelectronic devices previouslydisclosed by the present inventor.

For example, my U.S. Pat. No. 9,432,021 (incorporated by referenceherein) disclosed a novel low power micro- or nano-processor called aRemote Independent Microsystem (RIM). The RIM family includessystem-on-a-chip devices based on magnetoelectronic gates, which areversatile and be configured as both memory and/or logic circuits. Thesedevices are extremely inexpensive, disposable, and optimal forsingle-use cases. In one category of these devices, the RIM includes oneor more sensors (detection elements), a transducer circuit that teststhe value of the sensors, a signal processing logic circuit thatinterprets the result of the test, a nonvolatile memory that storesresults of the tests, a timing or input circuit that determines when(and how often) tests are performed, and a readout circuit that displaysthe result of the test in a form that can be read by an externaloperation. The RIM is introduced in column 5 line 6 of '021 and adetailed description begins on column 9 line 58. An embodiment of a RIMis illustrated with a sketch in FIG. 3B of '021. Other forms of CMOSbased hybrid semiconductor devices which can function as both logic andmemory may be suitable for applications of the present invention aswell. For example, in U.S. Pat. No. 8,988,103 to Liu (incorporated byreference herein) a floating gate based CMOS device is described thatemploys capacitive coupling for both logic and memory functions, toimplement a particular type of boolean logic circuit: a majoritycircuit. Other similar devices with hybrid functionality may be employedin some embodiments of the present detectors to effectuate the necessaryprocessing and memory functions described herein.

A similar embodiment is shown in FIG. 3 herein. As in FIG. 3B of '021,FIG. 3 illustrates a perspective sketch of a preferred embodiment of atypical package for an integrated system on a chip RIM 300. The figureshows a number of the components discussed above, including:

Signal processor logic and memory components for the RIM system situatedon a common substrate 350;

battery 320;

CNT based sensor [e.g. FIG. 2] 330;

Components for one form of passive readout 362, 364 and 368.

Details of active and passive readout functions are discussed below. Inthis preferred embodiment, one part of the passive readout is a fluidchemical 1 that is retained in a hollow storage volume or chamber 362(this was also referred to as a “payload” in '021). A second part of thepassive readout is fluid chemical 2 that is retained in a separatehollow storage volume or chamber 364. A thin membrane 368 preferablyseparates chemicals 1 and 2. Chemicals 1 and 2 are chosen to bereactants in a chemical process in which the product of the process is adye molecule (not shown). In this preferred embodiment, the dye moleculeresults if the membrane is ruptured so that chemicals in the twopayloads are permitted to interact or mix. A rupture in membrane 368 canbe caused to occur when the sensor exceeds a target threshold and thecircuit 350 activates a microelectronic mechanical structure (MEMS) ofany well-known suitable forms in the art near the membrane (not shown).It will be understood that membrane 368 may include one or more separatelayers or materials, and that the boundary surfaces of chambers 362 and364 are preferably transparent. This embodiment was discussed in '021 inthe context of applications where the RIM could be employed in anaqueous environment and chambers 362 and 364 protected chemicals 1 and 2from the environment.

Variations of this technique will be apparent to those skilled in theart from the present teachings. For example, Chemical 1 can be a dyemolecule that is initially stored in opaque chamber 362. Transparentchamber 364 is initially empty. Activation of a MEMS structure rupturesmembrane 368 and the dye molecule fills a portion of transparent chamber364, where it can be detected by optical methods, including a human eye.

For applications discussed in this disclosure, RIMs 300 are typicallydeployed in a dry environment. For such cases another variation issimpler. A dye molecule is initially stored in opaque chamber 362 andchamber 364 is omitted. Activation of a MEMS structure ruptures membrane368 and the dye molecule coats a substantial portion of the outsidesurface of the RIM package. The dye can be detected by optical methodsand the presence of the dye does not hinder functions of the RIM.

The presence of the dye on the exterior of the RIM 300 can be used torepresent the result of the chemical detection process, a single bit ofinformation that indicates the presence or absence of the target. It canbe called a “readout molecule,” and can be “read” using a “readoutreceiver” and a process described below. The selection of particularreadout (or payload) chemicals can be determined using routine skillbased on application goals, system requirements and the environment thesensor is to be used in. For example, in instances where humanobservation is to be used to detect an output, the resulting dye (insufficient quantities) should be detectable to a human eye. In otherinstances, because of cost, convenience or security, the resulting dyecan be engineered to be detectable only by additional machine assistanceor interrogation, such as in the case of a change in infrared orultraviolet, radiation, etc. Other examples will be apparent to thoseskilled in the art and further details are included below. In someapplications, as noted herein, the detection system and the resultingreadout substance (which, in a preferred approach is also a chemical)may be substantially undetectable to a human visual system to avoiddetection, such as in an surveillance application

Combining microfabricated detector elements, such as the CNT element ofFIG. 2, with system-on-a-chip structures such as the RIM results in anew method of detecting chemical or biological agents associated withhazardous materials. The basic method was introduced in '021 and isdescribed herein with further detail. Referring to the schematic drawingof FIG. 4, all of the components of system 100 are microfabricated on asingle chip 400. A significant operational difference betweenmacroscopic system 100 and microscopic system 400 is that the former isreadily connected to a broad information system or network. By contrast,the readout signal of 400 is relatively weak and it must be received bya macroscopic subsystem 410 and then amplified and/or converted to adifferent format in order to make the output 460 available to a broaderinformation system.

In the following sections, structures, means and methods for providingreadout to a receiver 410 are described first. Following this,techniques for employing the novel chemical or biological sensor systemare discussed.

A RIM 300 can provide output of results stored in memory in several waysand basic techniques were introduced by the inventor in US patent '021.In a first method, a RIM with a sufficiently large battery can useactive readout to transmit data to a receiver. The RIM includes atransmitter and transmitting antenna. Transmission could use convenientfrequencies in the microwave band. In a preferred technique, the RIMemploys a near field antenna as a compact alternative to a dipoleantenna. For the purpose of this specification, the term near fieldantenna will be used in contrast with the more typical dipole antenna.Electromagnetic radiation has coupled electric and magnetic fields thatoscillate together. A dipole antenna generates an oscillating electricfield and the magnetic field is created simultaneously. The dipoleantenna typically has a length of a quarter of a wavelength of thegenerated electromagnetic radiation. A near field antenna generates anoscillating magnetic field and the electric field is createdsimultaneously. This kind of antenna typically has a coil geometry andthe spatial dimensions are unrelated to the wavelength and can be muchsmaller than the wavelength.

Near field antennas have been developed for commercial radio frequencyidentification (RFID) applications. An example of such an antenna isused for subcutaneous implantation in pets or humans. Dimensions of sucha cylindrical antenna are approximately 1 mm in diameter and 2 mm inlength. The operating frequency is tuned for the commonly used RFIDfrequency of 13.56 MHz, and the effective radius of transmission is 5 to10 cm. Lithographic processing may result in a near field antenna withdimensions that are smaller by a factor of ten or more. It is importantto note that the near field antennas developed for RFID can be used foreither transmission or reflection (also called backscattering). Theformer is typically called active readout. The latter is passive readoutand is described further below.

A second kind of readout and detection of the RIM state is passive andrequires very little power. A RIM using passive readout can operate witha small battery and the overall RIM dimensions can be reducedsignificantly. Two forms of passive readout can be described. The firstcategory relates to the description in '021 and the extended discussionabove., A circuit can trigger an integrated MEMS (Micro ElectroMechanical Structure) or NEMS (Nan Electro Mechanical Structure) devicethat releases a readout molecule which has a chosen optical response.For the applications in this disclosure, the readout molecule preferableremains fixed to the surface RIM so that it can be more easily detected.One example is a dye molecule that reflects a conveniently chosenwavelength of light. A second example is a fluorescent molecule that canbe excited by a light source and then fluoresced with a spectrum that'sreadily detected. In this form, the released molecule can be considereda readout molecule as it represents a single bit of information. It willbe understood that a RIM may have one or more readout molecules in oneor more chambers to indicate detection of different target chemicals.

The second form of passive readout employs the same antenna describedabove but used in a passive mode. An antenna tuned to the frequency ofan input wave will reflect a small portion of the input power when thecircuit impedance attached to the antenna differs from the intrinsicimpedance of the antenna. In the simplest form, an appropriate antennacan be configured to be enabled or disabled by sending a current pulsethrough either a fuse or anti-fuse. As a specific example of this, theantennal coil can be fabricated to include a conducting wire fuse thatforms a short circuit across the two terminals (refer also to '021). Asfabricated, the antenna is disabled. A current pulse applied to the fusedestroys the fuse and enables the antenna. A bit of information isthereby represented by an enabled or disabled antenna, and therefore thepresence or absence of a reflected pulse of microwave power in responseto an interrogation pulse. The antenna can be called a readoutreflector. Any RIM may have one or more readout reflectors, each tunedto a different resonant wavelength. The advantage of this technique isthat it is simple and requires no on-chip power.

Alternatively, the antenna can transmit a string of data using an RFIDtechnique, a well known method briefly described as follows. In thepresence of incident microwave radiation at the tuned frequency, aportion of the power received by the antenna is converted to current anddirected to a subcircuit consisting of a rectifier and capacitor (notshown). The rectified current charges the capacitor and the chargedcapacitor provides dc current to the other circuits of the RIM. Aportion of this current may be used to generate microwaves transmittedby the antenna. Alternatively, a portion of the current is converted toa voltage and applied to the memory. The resulting readout current ismodulated as a function of time and superposed with a small microwavetransmission that is created in the form of reflected power. Readout ofthe nonvolatile memory cells has the form of a low frequency digitallymodulated current that also is applied to the antenna. The result is atransmission of resonant frequency microwaves with an amplitude that ismodulated by a bit-stream that contains the information stored in RIMmemory. The modulated microwaves are received and decoded by standardtechniques. An advantage of this form of readout is that it requires noon-chip power. Another advantage is that it can transmit a stream ofmany bits. Therefore, this technique can be used for a RIM that may havemultiple sensors or that may include on-chip data processing thatresults in a relatively large amount of data.

Referring again to FIG. 3, the preferred embodiment of the simplifiedRIM 300 functions as a disposable, one-time detector of a targethazardous chemical (or chemicals). A volatile molecule associated withthe targeted chemical adsorbs to the surface of chemical detecting array330. A circuit in logic processor 350 is programmed to test the statusof the sensor at periodic intervals. When a target molecule is present,the sensor voltage exceeds a threshold value. An activation circuit (notshown, but which may take any number of well-known forms) in processor350 sends a voltage pulse to a MEMS device adjacent to membrane 368 (notshown) and the membrane ruptures. Chemicals 1 and 2 are then free to mixtogether and a dye readout molecule forms in the volumes 362 and 364. Ifthe RIM is recovered, the status of the sensor is determined bymeasuring the value of an amplitude or intensity of reflectance of lighthaving a wavelength corresponding to the color of the dye. If the RIMremains in a remote location that cannot be directly accessed, thestatus of the sensor is interrogated and determined in the same wayusing a broad and higher power beam of light. The reflection from acollection of RIMs in a larger area (several square meters) can bemeasured with an appropriate detector remotely as well for physical andchemical surveillance purposes.

The operational goal of the new approach is to take advantage of themicroscopic size and low cost of microfabricated sensing chips such asRIMs. Large number of chips can be distributed widely, and techniquesthat involve attaching RIMs to common articles are discussed below.Detection of hazardous biological or chemical agents is increasedbecause such approach only requires success of only a small fraction ofa large number (i.e. hundreds or thousands) of distributed chips. Thepresence of the chips will preferably be unknown to observers and isharmless to the environment. The transmission of Readout data from anyRIM 400 (FIG. 4) to a readout receiver 410 has limited range. For thecase of either active or passive microwave transmission, the range mightbe the order of meters in the former case and the order of 10 cm in thelatter case. For passive readout using a readout molecule, optictechniques can be used with a range varying from the order of 1 cm tothe order of 10 meters. Operation of the overall approach involvestechniques of chip dispersal, recovery, and operation of the readoutreceiver.

Key steps in a surveillance or chemical detection process 500 aresummarized with the flowchart depicted in FIG. 5. Steps in the flowchartcan be described as follows:

Disperse RIMs 505: RIMs are dispersed over a variable area of interest,or a set of articles. As one example, RIMs can be embedded on thesurface of common objects or articles. Alternatively, they can bedispersed as an aerosol and applied as a thin chemical detectioncoating/layer.

Exposure 510: RIMs are exposed to an environment at the site or articlethat may include target chemical or biological agents.

Sense 515: A circuit (or circuits) is activated and detects the presenceor absence of one or more targets. Activation of the circuit may occuronce or on multiple occasions with predetermined timed intervals.Activation may occur in response to externally applied trigger signals.

Record Data 520: The circuit writes the result to nonvolatile memory inbinary form.

Analyze Data 525: The data are compared with benchmark values stored inmemory. The comparison determines if the result meets a threshold ofsignificance.

Create a readout marker 530: If a target agent is identified, astructure or chemical is created or enabled as a marker that responds,at a later time and under appropriate circumstances, to externallyapplied electromagnetic or optical radiation.

The above steps detect a specific target agent that responds only tonarrowly specific analytic techniques. The result is converted to amarker that is readily detected by common and readily availabletechniques involving, for example, optics or longer wavelengthelectromagnetic waves.

Recover RIMs 540: The RIMs can be optionally collected and recovered.For example, if RIMs are attached to a carrier article, that article canbe recovered at an appropriate facility.

Alternatively, Move Readout Receiver to Field site of RIMs 535: TheReceiver is moved to a location proximal with the distributed RIMS todetect their state.

Readout Results 545: The Readout Receiver may receive an activetransmission from one or more RIMs (active mode). Alternatively, theReceiver may interrogate the RIMs with optic or electromagneticradiation and receive (detect) a response (passive mode).

Output Results to Information Network 550: The Readout Receiver storesthe results and makes them available to an information network.

Novel Application/Distribution Techniques

Another focus of this disclosure is the consideration of applications ofthe RIM based detector that involve surveillance or reconnaissance of anillegal activity involving dangerous and/or illicit chemical orbiological agents. For example, an individual involved in an illegaland/or harmful activity may be working with these materials in asecluded and/or confined area to avoid detection. Any dangerous and/orillicit chemical or biological material associated with such activitycan be a target of inspection. To detect such illegal activities,different mechanisms to surreptitiously introduce RIM detectors to thearea/location can be used so that they are placed in sufficientproximity to the target of inspection. The RIMs are initially set to bedormant or inactive. When activated, the RIM detectors perform a logicaldetection test routine in order to sense whether a target detectedsubstance is a dangerous or illicit chemical and then record a responsethat indicates whether the test is positive. The RIM detectors are thencollected and queried. Alternatively, the RIM detectors may remaindispersed in their sensing location but queried remotely. In any case,it is preferable, of course, in such surveillance applications, that theRIM detectors and their readout markers should not be observed (or beobservable) by the targeted individual(s).

One embodiment of a detector application/distribution method 600 isdepicted with the flow chart in FIG. 6. At step 601 any number of RIMdetectors can be fixed to (or coated on) the surface of a sheet ofpaper, another paper based product (paper towel, envelope, box, airfilter, paper mask, product packaging, book, passport, travel documentsetc.), or any other convenient article 605 which has surfacecharacteristics that allow for adherence of the RIM detectors. In apreferred paper article embodiment, the process of “fixing” is meant toimply that each RIM is pressed into the surface of the paper withsufficient pressure (or attached with a secondary adhesive so) that itadheres to the surface. In some instances they may be incorporatedwithin the fibers of the paper directly as part of a paper makingprocess. For example, passports may include exterior binding paper orinternal sheets in which the elements are incorporated. In otherinstances a liquid adhesion mixture can be applied to form a thin layerof detection elements, and such that after exposure to air a carrierliquid evaporates, leaving the RIMs on the surface of the article.Because of their small size, however, the loss of some number ofdetectors from being peeled off or otherwise removed should not bedetectable. The RIM preferably has a placement at or near the surface sothat volatile molecules in the ambient environment (or on the hands ofthe targeted individual or some other surface) can come in contact withthe sensor surface.

The paper then can be introduced into the target locationinconspicuously as an article of correspondence, advertising, packingreceipt, etc. at step 606 to a target location 607. The RIMs 300 willnot be observable by a targeted individual with the naked eye becausethey are microscopic in size. After spending sufficient time at step 610in the target location 611, the paper (or other article) can berecovered in the form of waste or of a continued correspondence, or anyother suitable form at step 620. Once recovered, the RIMs 300 on thepaper can be tested at a facility 640 to determine their status at step645.

In a variation of this first embodiment, some forms of RIM detectors canbe imprinted to a paper article 605 within a print ink/dye or tonermixture, as part of a printing process, or photocopying process. Forexample, in a conventional ink jet printer, the ink drops areapproximately 100 microns in size. By engineering the RIM detectors 300to be much smaller than this and have reasonable resistance to heat, itis expected that they can be accommodated and printed by a typicalprinting head by their incorporation within a larger inkjet droplet.

In dry toner applications, the RIM detector 300 can be included as partof the print powder mixture. The size of toner particles (which form thebulk of the mixture) is extremely small (typically on the order of 10microns) and therefore the detectors (which form the detecting part ofthe mixture) must be of equivalent size, weight and preferably shaped ina similar manner to the toner particles to exhibit similar adhesioncharacteristics. In this manner the detectors are able to adhere topaper using the same or similar mechanism as the toner particles, i.e.,using electrostatic, magnetic and/or surface tension attractions. Itwill be understood that the imparting of the detectors to the paper maybe achieved by a separate dedicated pre or post print station within aprinter apparatus as well.

In such applications it is expected that some portion of the RIMdetectors may be rendered unusable if they are completely covered withink/toner. However, as long as a reasonable number are exposed on aprinted surface they can react with a target chemical to yield usefultesting and results. Furthermore, in applications for detection of anenvironmental condition (such as temperature) the mixing or lack ofsurface exposure may be less critical, again, subject to the RIMdetector state being readily detectable/readable. For ease of use andflexibility, in a printing application the inclusion of RIM detectorsmay be implemented on a selective character by character basis on aprinted article. In this manner they can be selectively employed wherenecessary for an application

In another embodiment of a distribution/application technique, a numberof RIMs can be fixed to a piece of fabric, either directly or as part ofa decal/logo. The process of “fixing” can be performed in the samemanner as provided above. In some instances the RIM detectors canintroduced to a surface portion of the body of the article during awashing/drying process depending on the fabric properties,size/adherence of the RIMs, etc. For example, they may be incorporatedwithin a solid/liquid detergent, or dryer paper softener, or otheravailable mechanism. The piece of fabric is then introduced into thetarget location as an article of clothing provided to inhabitants orworn by a visitor surreptitiously to a targeted location. The fabric canbe recovered and the RIMs can be tested to determine their status.

In a variant of this technique, an electronic skin compatible andflexible patch can incorporate the RIMs to detect the presence ofparticular chemicals, toxins, etc., in the sweat or other body fluid ofa living organism. For example, some useful biomedical applications mayinclude detection and measurement of alcohol and/or glucose in aperson's sweat through flexible patches, tattoos, etc.

In yet another embodiment of a distribution/application technique, theRIMs can be aerosolized, or applied directly as a particulate aerosol toform a thin coating or layer of detection elements. An aerosol is asuspension of solid or liquid particles in a gas such as air ornitrogen. Typically the aerosol is contained in a pressurized containerwith a nozzle for dispensing the contents. The RIMs may form a dryaerosol or they can be mixed with a liquid, forming a suspension, andthe liquid can be converted into an aerosol that is sprayed on anyconvenient surface to form an ultra-thin layer of detection elements.

A flowchart that describes an example of a process 700 for thedistribution, sampling and testing of RIMs using an aerosol is providedin FIG. 7. In this example, an aerosol of RIMS is sprayed on the insidesurfaces of the trunk of a rental car at step 710. The car is madeavailable to a party that is under surveillance for illegal activity atstep 715. The monitored party may store a dangerous and illegalsubstance in the trunk for some time at step 720. At step 725 the rentalcar is returned and the RIMs on the inside surfaces of the trunk arequeried at step 730 for example using an optical sensor. It will beunderstood that this example is presented with the article in questionbeing a vehicle, and similar steps may be employed to distribute andsample other articles, including consumer products or other items thatare handled by humans in every day activities.

To provide a further description of application and distribution usingaerosol, the particulate portion of an aerosol is called the ParticulateMatter or PM. PM is measured as a particle diameter and is denotedtypically in units of microns. The PM in a conventional aerosol canusually range from 0.001 to 100 microns. Typical diameters of RIMsdiscussed in this invention application preferably range from 1 to 100microns and therefore qualify as equivalent in size to Very Fine orsmaller droplets (according to the ASABE S572.1 Droplet SizeClassification Chart) and can form a particulate aerosol suspension.This size range is the same as atmospheric dust (diameters of 50 micronsand smaller) and coal dust (diameters of 1 to 100 microns) andconsequently RIM detectors in an aerosol can be expected to havecharacteristics of dispersion and adhesion that are similar to aerosolsof atmospheric or coal dust.

In other instances the RIMs can be mixed with a liquid (e.g. water,methanol) so that a RIM coated with the liquid can form an aerosolsuspension. In either case, the density of the aerosol can be controlledin any conventional manner. The RIM detector aerosol can be applied to atarget surface of an article as a spray using the liquid as a carrierand the RIM detector particulates. Similar to dust, RIM detectors can beexpected to stick to many surfaces by normal forces of adhesion.Furthermore, it is expected that adhesion to particular surfaces can beoptimized using routine skill based on adjusting surface textures,particle size/weight, etc. For example the weight/shape/texture of a RIMdetector can be altered as desired using routine skill duringmanufacturing form by including an additional backing/coating or surfacetreatment.

In some applications a number of controlled RIM aerosol treatments canbe performed at a location (akin to how pest control services or pest“bombs” work) to prepare an area, site or enclosed building for testing.By blanketing and interrogating an entire enclosed space, opportunitiesare created for detecting other potential chemicals, leaks, etc. Afterthe liquid carrier evaporates, the aerosol based RIMs will adhere to thesurface so that the sensor can be presented to ambient conditions. Itwill be understood by those skilled in the art that it may not benecessary to use a pressurized container, and the RIM detectors may beapplied in suspension, or part of another liquid, as long as they can bereasonably and uniformly applied and exposed after thecarrier/suspension liquid evaporates. For example, some types ofpersonal care products (perfume, lotion, solid/liquid soaps, shampoos,sprays, hand sanitizers) and even potable water may be modified toinclude a desired concentration and number of the novel RIM detectors.The RIM detectors would then adhere to a person's (or other organism)skin, hair, etc. so that they become active, mobile sensors tracking theperson's exposure. Since the RIM detectors are biologically inert theyalso can be incorporated in small doses in food products for detectionof some internal condition or target material.

The aerosolized RIM detector spray may be also applied to walls,ceilings, windows of structures, containers or personal articles such astools and cars. For example, in a surveillance application, it may bedesirable to coat window panes with a thin film that reacts to ambientwithin an area and is detectable from outside a structure. As before,the RIMs can be recovered by removing them from the surface with a clothand an appropriate solvent.

In commercial applications the RIM detectors can be implemented asdesired on different correspondence/articles to solicit information onthe presence of particular chemicals in consumer's homes, rentalvehicles, etc. For example, the presence of particular food odors,fragrances, pet smells, ambient household scents, or any other targetchemical can be detected and acted on for marketing and sales purposes.The presence of chemical markers in a rental vehicle (cigarette smoke,drugs) may be used to identify violations of rental contract agreements,as in the case of consumers transporting unauthorized substances. Inindustrial applications, the exposure by workers to target chemicals canalso be detected and analyzed to determine compliance with safetystandards. For example, the RIM detectors can be incorporated withinwork clothing, masks, gloves, or other surface, and interrogatedregularly during a workday to identify exposure to specific chemicalelements, including any harmful or undesirable substances. The detectionprocess may be done with or without the knowledge of employees toincrease security, maintain privacy, etc. A similar process could beadopted within a secure facility, including a penitentiary, to detectinteractions by inmates with improper or illegal substances.

Readout Receiving

As described in '021 and mentioned above, the result that is stored inthe RIM sensor chip can be represented by the creation of a readoutmarker. A readout receiver (410 in FIG. 4) addresses, receives andinterprets the marker to make that result available to an informationsystem. In one implementation of this technique that was describedabove, two component chemicals are separated by a membrane and an outputpulse to a MEMS or NEMS device ruptures the membrane enabling the twoconstituents to form a dye. Alternatively, a dye molecule can be storedinside a volume bounded by a membrane. An output pulse ruptures themembrane and allows the dye to escape, adhere to the surface of the RIM,and thereby become visible or detectable by an instrument/machine. Thereare many optical techniques that are highly sensitive for the detectionof trace quantities of die. To detect small quantities of dye, forexample on a page of paper or other article, one standard technique isdescribed as follows. White light is directed at the article (e.g.paper) and the reflected light is recorded by two separate detectors.The detectors can by photo-diodes or photo multiplying cells. To detectred dye, for example, one detector is sensitive to red light and thesecond is sensitive to green light. The output of the two detectors iscompared. A recorded output from the red photo-detector that is largerthan that from the green photo-detector can be determined with highsensitivity.

Alternatively, one can substitute a fluorescent molecule for the dyemolecule. In this case, detection involves applying a pulse of ultraviolet light to the article. The ultra violet creates excitations in thefluorescent molecules and the excitations decay by emitting photons ofvisible light. Detection involves timing the shutter of a photo-detectorto open immediately after the termination of the ultra violet pulse.

As is apparent from the above discussion, the particular sensor form anddetection mechanism can be tailored, customized and optimized based on atarget application. Furthermore, in analogy with “Field ProgrammableGate Array” technology, multiple sensors and associated circuitry can befabricated on any RIM. The user can programmatically choose the sensorsto be used. Circuits and/or chip sectors associated with individualsensors can be activated or inactivated by using fuses or antifuses, ornonvolatile switches as disclosed in U.S. Pat. No. 9,735,344. Anadvantage of this approach is that manufacturing a single RIM design canaddress a variety of different sensing needs. This provides moreflexibility for applications. The results of a number of sensors can bestored in nonvolatile memory and read out by techniques described inearlier text.

Sensors of Environmental Conditions

Previous discussion has described one focus of this disclosure,applications of the RIM based detector that involve surveillance orreconnaissance of an illegal activity involving dangerous and/or illicitchemical or biological agents. Other applications that use the samemethods are apparent. The inventive RIMs can be used for detectingenvironmental conditions as well, such as temperature, humidity, light,radiation, etc. FIG. 3 can be used to depict a RIM with a temperaturesensor as structure 330, rather than a chemical adsorbent. The RIM maybe programmed to activate the sensor periodically. Alternatively, theRIM may be periodically activated by a microwave pulse. In either case,if the temperature exceeds a threshold value, an output would trigger anevent that would be detected externally. The events and detection couldbe implemented in the same manner as described for the RIM with achemical sensor.

Currently there are two kinds of temperature sensors that are commonlyused with integrated circuits. Either or both can be made with amicrofabrication process and could be used in connection withembodiments of the present invention for detecting environmentalconditions.

(1) Resistance Temperature Detector (RTD).

RTDs commonly use a thin metal film resistor. Platinum (Pt) resistorscan be used over a large temperature range, −200 to 600 C. Of course,most chips that include semiconducting devices operate in a reducedrange of 0 to 100 C and will not be suitable for performance in abroader temperature range. As an example of plausibility, an appropriatemetal film resistor can be designed with the following considerations.Thin film Pt has resistance per square of about 1 Ohm for a thickness ofabout 30 nm. A thin film wire could be fabricated with 400 nm (0.4 um)width. A ten micron length then has resistance of 25 squares=25 Ohms.The wire could be formed as a meander line with 4 repeats that giving atotal resistance of 100 Ohms. A bias current of 100 microAmps produces avoltage of 10 mV which is readily detected with good accuracy. Carefulanalysis will determine the requirements for a given application. Forexample, if threshold at 100 C is desired an integrated sense amplifierthat has an appropriate accuracy can be engineered using knowntechniques. Similarly, the output voltage would be adjusted so that thesense amplifier has the required accuracy.

(2) Semiconductor-Based Sensors:

These sensors typically are comprised of two identical diodes that havevoltage-current (V-I) characteristics that are sensitive to temperatureand therefore can be used to monitor temperature changes. They offer alinear response but have lower accuracy (about 1 to 5 C) than RTDs. Asnoted above, they also have a narrower temperature range (−70 to 150°C.).

For applications related to environmental conditions, the size of theRIM may not be crucially important. It may therefore be convenient tomanufacture the RIM with dimensions of order 1 to 10 millimeter. In thiscase, microwave readout techniques can employ dipole antennas withrelatively large dimensions. Passive dipole antennas can be detected atrelatively large distances. The larger RIM may include a larger batterywith circuitry to increase the detection distance. A larger RIM, asdescribed in this paragraph, has several advantages in comparison withprior art RFID tags. Conventional RFID tags may contain the order of 100bits of information, but these data are of the form “write once, readmany.” The data may be an identification code or serial number, forexample. But that number was written to nonvolatile memory and cannot bechanged. By contrast, the RIM is a dynamic device that can perform senseand analysis operations. The RIM may contain information bits thatprovide identification. Of greater importance, the RIM can performoperations and add (or change) data that are stored in memory during thelifetime of operation. These data may represent, for example, a historyof temperature or of exposure to other environmental conditions such ashumidity or a variety of forms of radiation.

The examples above are merely illustrative of the general principlesinherent in the teaching of the present invention. Other variations willbe apparent to skilled artisans, and the present invention should not beinterpreted to be restricted to such specific embodiments and examples.

What is claimed is:
 1. A chemical detection system situated on a singlesemiconductor chip, comprising: a carbon nanotube (CNT) sensor circuitconfigured with a resistance state that is responsive to the presence ofa target chemical and/or target environmental condition when exposed toa target environment; a transducer coupled to the CNT sensor circuitconfigured to detect said resistance state and generate an outputcorresponding thereto; a magnetoelectronic (ME) processing circuitcoupled to said transducer and including one or more magnetoelectronicgates adapted to perform a first sequence of operations during anoperational mode on said output from said transducer; wherein adetection output is generated by the ME processing circuit having adetection value based on said first sequence of operations confirmingthe presence of said target chemical and/or target environmentalcondition; further wherein said ME processing circuit is configured tonot consume power in a quiescent mode; a non-volatile memory coupled tosaid ME processing circuit for storing said detection value; a firstreadout substance situated in a storage chamber of said singlesemiconductor chip; wherein said first readout substance includes a formand quantity sufficient to be identified as first readout output by anunaided human eye; one or more micromechanical structures responsive tosaid detection output, and adapted to cause said first readout substanceto be released from said storage chamber in response to said detectionvalue; a transmitter and antenna coupled to the ME processing circuitand adapted for communicating said detection value using microwaveradiation as a second readout output; wherein a presence of said targetchemical and/or target environmental condition can be determined throughtwo separate readout outputs: 1) by an unaided human eye detecting saidfirst readout substance released from said chamber; and 2) by decodingsaid microwave radiation communicating said detection value.
 2. Thesystem of claim 1 further including a second storage chamber connectedto said storage chamber and containing a second readout substance. 3.The system of claim 2 further including a membrane separating saidstorage chamber and said second storage chamber, and which is adapted tobe ruptured by said one or more micromechanical structures to permitmixing of said first readout substance and said second readoutsubstance.
 4. The system of claim 3 wherein a third readout substanceresults from said mixing.
 5. The system of claim 1 further including amembrane associated with said storage chamber which is adapted to beruptured by said one or more micromechanical structures to permitrelease of said first readout substance to an exposed external portionof said single semiconductor chip.
 6. The system of claim 1 wherein saidtarget chemical is a chemical and/or biological agent hazardous toliving organisms.
 7. The system of claim 1 wherein the CNT sensorcircuit is coated with a polymer that reacts in the presence of saidtarget chemical.
 8. The system of claim 1 wherein the singlesemiconductor chip is affixed to or embedded in a paper based substrateor an article of clothing.
 9. The system of claim 1 further including anantenna adapted for near field communications with a separate targetchemical interrogation system.
 10. The system of claim 9 wherein saidantenna enables passive readout and is activated by a readout pulsegenerated by the ME circuit.
 11. The system of claim 1 wherein thesystem functions as a one-time disposable detector of the targetchemical.
 12. The system of claim 1 wherein the ME processing circuit isconfigured to measure the presence of said target chemical at programmedintervals.
 13. The system of claim 1 wherein the single semiconductorchip is incorporated and made part of a solid powder or liquid mix. 14.The system of claim 1 wherein the ME processing circuit is configured tobe inactive until queried by a separate readout system.
 15. The systemof claim 1 wherein the single semiconductor chip is adapted to bereproduced and disseminated with single semiconductor chip chemicaldetections system in a distributed targeted area.
 16. A chemicaldetection system situated on a single semiconductor chip, comprising: acarbon nanotube (CNT) sensor circuit configured with a resistance statethat is responsive to the presence of a target chemical and/or targetenvironmental condition when exposed to a target environment; atransducer coupled to the CNT sensor circuit configured to detect saidresistance state and generate an output corresponding thereto; amagnetoelectronic (ME) processing circuit coupled to said transducer andincluding one or more magnetoelectronic gates adapted to perform a firstsequence of operations during an operational mode on said output fromsaid transducer; wherein a detection output is generated by the MEprocessing circuit having a detection value based on said first sequenceof operations confirming the presence of said target chemical and/ortarget environmental condition; further wherein said ME processingcircuit is configured to not consume power in a quiescent mode; anon-volatile memory coupled to said ME processing circuit for storingsaid detection value; a readout substance situated in a storage chamberof said single semiconductor chip; wherein said readout substance is ina form and quantity that is not detectable by an unaided human eye; oneor more micromechanical structures responsive to said detection output,and adapted to cause said readout substance to be released from storagechamber in response to said detection value; a microwave antenna coupledto the non-volatile memory and responsive to an interrogation signal toenable passive readout of said stored detection value; wherein apresence of said target chemical and/or target environmental conditioncan be determined through two separate readout outputs: 1) byinterrogating said stored detection value; and 2) by an optical detectorsystem optically detecting said first readout substance.
 17. The systemof claim 16, wherein said microwave antenna is selectively activatableby a current pulse generated by the ME processing circuit.
 18. Thesystem of claim 16 wherein said interrogation signal is a microwave beamand/or pulse.
 19. The system of claim 16 wherein a voltage bit streamfrom said stored detection value can be superposed with a reflectedmicrowave signal to form a signal transmitted to an interrogatingreceiver.
 20. A chemical detection system situated on a singlesemiconductor chip, comprising: a carbon nanotube (CNT) sensor circuitconfigured with a resistance state that is responsive to the presence ofa target chemical and/or target environmental condition when exposed toa target environment; a transducer coupled to the CNT sensor circuitconfigured to detect said resistance state and generate an outputcorresponding thereto; a magnetoelectronic (ME) processing circuitcoupled to said transducer and including one or more magnetoelectronicgates adapted to perform a first sequence of operations during anoperational mode on said output from said transducer; wherein adetection output is generated by the ME processing circuit having adetection value based on said first sequence of operations confirmingthe presence of said target chemical and/or target environmentalcondition; further wherein said ME processing circuit is configured tonot consume power in a quiescent mode; a non-volatile memory coupled tosaid ME processing circuit for storing said detection value; a firstreadout substance situated in a storage chamber of said singlesemiconductor chip; wherein said first readout substance is in a firstform and first quantity sufficient to be identified as first readoutoutput by an unaided human eye; a second readout substance situated insaid storage chamber of said single semiconductor chip; wherein saidsecond readout substance is in a second form and second quantity whichis not detectable by an unaided human eye; one or more micromechanicalstructures responsive to said detection output, and adapted to causesaid first readout substance and said second readout substance to bereleased from said storage chamber in response to said detection value;wherein a presence of said target chemical and/or target environmentalcondition can be determined through two separate readout outputs: 1) byan unaided human eye detecting said first readout substance releasedfrom said chamber; and 2) by an optical detector system opticallydetecting said second readout substance released from said chamber. 21.The system of claim 20 wherein said optical detector system uses acolor-based photodetector detecting light reflected by said secondreadout substance.
 22. The system of claim 20 wherein said opticaldetector system uses a photodetector detecting light reflected by afluorescent molecule in said second readout substance.